Toyota Corolla Heater Not Working: Causes & Fixes

During the freezing cold of the summer, you would need your car heater to keep you warm. The worst-case scenario would be when you discover that your Toyota Corolla heater is not working. There could be a ton of reasons for this which will depend on the model you’re driving. There are also a good number of fixes you can try out before considering taking the car to the mechanic.

Your car’s heating system consists of a heater core, HVAC control, a heater fan, and works with the car’s coolant system to produce the heat you so much need. This is done when the hot coolant is drawn into the heater core and then the heat is blown into the cabin through the heater fan. You get to decide just how much heat you want in the cabin using the HVAC controls.

toyota corolla heater not working

In this guide, you will find the likely causes of your Toyota Corolla heater problems and the fixes that actually work.

Toyota Corolla Heater Not Working: Likely Causes

There are many reasons why your car heating system would malfunction and this means you would have to check each part for faults to confirm they are working fine before you can apply a fix. In some cases, the problem with the heating system could be a result of the malfunction of several components.

A Faulty Thermostat

A faulty thermostat would not only lead to issues with the heating system but also your engine’s cooling system.

Low Antifreeze

The antifreeze functions to ensure that the heat gets to the heater core. When the levels are low, the hot fluid won’t be able to get to the heater core so your cabin would remain cool.

A Faulty Heater Fan

The heater fan is meant to distribute the heat into the cabin. If it fails you might not get any warm air so your cabin would remain chill no matter how hard you try. A faulty heater fan would be a result of a mechanical or electrical problem.

A Clogged Heater Core

This issue is not very common, but it could be a problem with your heating system.  With continuous use, debris and other particles that get into the coolant system can clog the heater core and its passageways. This could be as a result of the radiator rusting from the inside.

Faulty HVAC Controls

Your HVAC controls are meant to determine the amount of heat you let into the cabin. If the control buttons, knobs, or touchscreen is broken, it could prevent the cabin from getting heated up as it should.

Bad Wiring or Blown Fuses

Heating problems could be due to electrical faults like blown fuses or faulty wiring. You should be able to fix issues with blown fuses by just replacing them, however, finding faulty wiring would require some skills that a mechanic would possess.

Toyota Corolla Heater Not Working: Fixes to Attempt

Clean or Replace the Heater Core

If you’re able to confirm that the heater core is the problem with the heating system, then you would have to get it fixed. Clogged heater core passageways can be cleaned, however, you should be ready to replace it if necessary. While clearing out the debris and particles could serve as an easy fix that would save you the cost of a replacement, getting the core replaced might be the best approach for long-term gains.

For this fix, you would have to take your car to the mechanic to get the best guidance about what to do next.

Fix the Broken Thermostat

Issues like a broken thermostat can be fixed without you having to go to the mechanic, however, you would require some form of technical knowledge to pull this off.

To fix the thermostat, you can follow the steps below

  • Let the car cool for about 20 minutes then lift the front end of the vehicle.
  • Locate the thermostat at the base of the radiator right between the core and the main hose. You might find it in a different place in your model, so you should consult your owner’s manual for guidance.
  • Remove the radiator cap
  • Place a bucket underneath the radiator, then detach the hose to drain the coolant.
  • Remove and replace the thermostat
  • Reattach the hose to the radiator.
  • Refill the coolant to the proper level and return the radiator cap back to its original position.
  • Bring your car down and then start the engine.
  • Watch if the heat comes on and take it for a test drive.

Fixing Low Antifreeze

A low antifreeze level is one of the most common reasons for heating problems. Fixing this problem is incredibly easy though you would have to purchase a funnel and new coolant.

To work on the antifreeze, you should

  • Wait till the car cools down before removing the radiator cap.
  • Place the funnel in the opening and put in the new coolant until you get to the proper level. Watch out for air pockets that would leave unnecessary space in the reservoir. Grab the main coolant hose and physically pump the coolant to remove any possible air pockets.
  • Place back the radiator cap.
  • Start the car and check if the heating system is working as normal.

Final Thoughts

There are tons of other issues though way less common that could be the problem with your heating system. You might be experiencing a radiator leak which is very possible in older cars. In such a case, you would have to repair or replace the radiator.

Another possible cause could be due to faulty heater valves. Your car’s heater valves could be manual or electronic. In the case of manual valves, repairs and replacing its faulty components could get this problem solved. With electronic valves, you will have to get your mechanic on the job as they are more complicated.